Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vaginal swabs of women with acute SARS-CoV-2 infection: a prospective study.

OBJECTIVE: To determine whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is present in the vaginal secretions of both reproductive-aged and postmenopausal women during acute SARS-CoV-2 infection. DESIGN: Prospective study. SETTING: A single tertiary, university-affiliated medical centre in Israel. Time period, 1 June 2020 through to 31 July 2020. POPULATION: Women who were hospitalised in a single tertiary medical centre, who were diagnosed with acute SARS-CoV-2 infection by a nasopharyngeal RT-PCR test. METHODS: Women were diagnosed with acute SARS-CoV-2 infection by a nasopharyngeal RT-PCR test. Vaginal RT-PCR swabs were obtained from all study participants after a proper cleansing of the perineum. MAIN OUTCOME MEASURES: Detection of SARS-CoV-2 in vaginal RT-PCR swabs. RESULTS: Vaginal and nasopharyngeal swabs were obtained from 35 women, aged 21-93 years. Twenty-one women (60%) were in their reproductive years, of whom, five were in their third trimester of pregnancy. Most of the participants (57%) were healthy without any underlying medical conditions. Of the 35 patients sampled, 2 (5.7%) had a positive vaginal RT-PCR for SARS-CoV-2, one was premenopausal and the other was a postmenopausal woman. Both women had mild disease. CONCLUSION: Our findings contradict most previous reports, which did not detect the presence of viral colonisation in the vagina. Although passage through the birth canal exposes neonates to the vaginal polymicrobial flora, an acquisition of pathogens does not necessarily mandate neonatal infection or clinical disease. Nevertheless, when delivering the infant of a woman with acute SARS-CoV-2 infection, a clinician should consider the possibility of vaginal colonisation, even if it is uncommon. TWEETABLE ABSTRACT: When delivering the infant of a woman with acute SARS-CoV-2 infection, a clinician should consider the possibility of vaginal colonisation.

Intensified environmental surveillance supporting the response to wild poliovirus type 1 silent circulation in Israel, 2013.

An emergency response was triggered by recovery of wild poliovirus type 1 (WPV1) of the South Asia (SOAS) lineage from sewage in southern Israel in April 2013 during routine environmental surveillance. Public health risk assessment necessitated intensification of environmental surveillance in order to facilitate countrywide monitoring of WPV1-SOAS circulation. This involved increasing sampling frequency and broadening the geographical area, for better coverage of the population at risk, as well as modifying sewage testing algorithms to accommodate a newly developed WPV1-SOAS-specific quantitative real-time RT-PCR assay for screening of RNA extracted directly from sewage concentrates, in addition to standard virus isolation. Intensified surveillance in 74 sites across Israel between 1 February and 31 August 2013 documented a sustained high viral load of WPV1-SOAS in sewage samples from six Bedouin settlements and two cities with Jewish and Arab populations in the South district. Lower viral loads and intermittent detection were documented in sampling sites representing 14 mixed communities in three of the five health districts in central and northern Israel. Environmental surveillance plays a fundamental role in routine monitoring of WPV circulation in polio-free countries. The rapid assay specific for the circulating strain facilitated implementation of intensified surveillance and informed the public health response and decision-making.

Silent reintroduction of wild-type poliovirus to Israel, 2013 - risk communication challenges in an argumentative atmosphere.

Israel has been certified as polio-free by the World Health Organization and its routine immunisation schedule consists of inactivated poliovirus vaccine (IPV) only. At the end of May 2013, the Israeli Ministry of Health (MOH) has confirmed the reintroduction of wild-type poliovirus 1 into the country. Documented ongoing human-to-human transmission necessitated a thorough risk assessment followed by a supplemental immunisation campaign using oral polio vaccine (OPV). The unusual situation in which ongoing poliovirus transmission was picked up through an early warning system of sewage monitoring without active polio cases, brought about significant challenges in risk communication. This paper reviews the challenges faced by the MOH and the communication strategy devised, in order to facilitate and optimise the various components of the public health response, particularly vaccination. Lessons learned from our recent experience may inform risk communication approaches in other countries that may face a similar situation as global polio eradication moves towards the 'End game'.

Molecular epidemiology of silent introduction and sustained transmission of wild poliovirus type 1, Israel, 2013.

Poliovirus vaccine coverage in Israel is over 90%. The last nine birth cohorts have been vaccinated exclusively with inactivated polio vaccine (IPV). However, between February and July 2013 type 1 wild poliovirus (WPV1) was detected persistently in 10 and intermittently in 8 of 47 environmental surveillance sites in southern and central Israel and in 30 stool samples collected during July from healthy individuals in southern Israel. We report results of sequence and phylogenetic analyses of genes encoding capsid proteins to determine the source and transmission mode of the virus. WPV1 capsid protein 1 nucleotide sequences were most closely related to South Asia (SOAS) cluster R3A polioviruses circulating in Pakistan in 2012 and isolated from Egyptian sewage in December 2012. There was no noticeable geographical clustering within WPV1-positive sites. Uniform codon usage among isolates from Pakistan, Egypt and Israel showed no signs of optimisation or deoptimisation. Bayesian phylogenetic time clock analysis of the entire capsid coding region (2,643 nt) with a 1.1% evolutionary rate indicated that Israeli and Egyptian WPV1-SOAS lineages diverged in September 2012, while Israeli isolates split into two sub-branches after January 2013. This suggests one or more introduction events into Israel with subsequent silent circulation despite high population immunity.

Insidious reintroduction of wild poliovirus into Israel, 2013.

Israel was certified as polio-free country in June 2002, along with the rest of the World Health Organization European Region. Some 11 years later, wild-type polio virus 1 (WPV1) was isolated initially from routine sewage samples collected between 7 and 13 April 2013 in two cities in the Southern district. WPV1-specific analysis of samples indicated WPV1 introduction into that area in early February 2013. National supplementary immunisation with oral polio vaccine has been ongoing since August 2013.

Placenta/birthweight ratio and perinatal outcome: a retrospective cohort analysis.

OBJECTIVE: The placenta weight/birthweight (PW/BW) ratio has been shown to be associated with certain long-term fetal outcomes; however, its association with short-term outcomes has not received much attention. Our aim was to assess the correlation between the PW/BW ratio and short-term adverse obstetrics outcomes in full-term, appropriate-for-gestational-age (AGA) newborns. DESIGN: Retrospective cohort study analysis using data from the McGill Obstetrical and Neonatal Database. SETTING: McGill University Health Centre in Montreal Canada. POPULATION: AGA neonates. METHODS: Three groups of full-term AGA neonates were created, according to their PW/BW ratio (high, normal and low), to be compared. Our primary outcome was the admission rate to the neonatal intensive care unit (NICU), and secondary outcomes included an Apgar score < 7 at 5 minutes, cord PH < 7.0, cord base excess (BE) ≤ 12, respiratory distress syndrome (RDS), patent ductus arteriosus (PDA), occurrence of apnoea episodes, breech presentation at delivery, caesarean section rate and status in discharge home. A logistic regression model was instituted to investigate the predictors for adverse obstetrics outcomes. MAIN OUTCOME MEASURE: Admission to the NICU. RESULTS: Compared with the group with normal PW/BW ratios, the high PW/BW ratio group was associated with increased rates of admission to the NICU, of Apgar scores < 7 at 5 minutes, of breech presentation and caesarean section. On the contrary, the low PW/BW ratio group showed decreased rates of NICU admission, breech presentation and caesarean section. CONCLUSIONS: A high PW/BW ratio is significantly correlated with short-term adverse perinatal outcomes. This ratio may be used as a new and simple warning sign to predict the possibility of short-term health risks for newborns.

Placental apoptosis in discordant twins.

OBJECTIVE: To investigate placental apoptosis in discordant dichorial twins. METHODS: Placental samples were obtained from 7 third-trimester suitable twins. Discordancy was defined as a >25 per cent difference in newborn birth weight. Light microscopy using hematoxylin and eosin (H&E)-stained paraffin slides and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling (TUNEL) methods were used to confirm the incidence of apoptosis. Investigators were blinded to pregnancy outcome. RESULTS: Both methods revealed that the incidence of apoptosis in the placentas of the smaller fetuses was significantly higher than in placentas of the larger fetuses. The incidence of TUNEL-positive cells in the former was 1.4+/-0.26 per cent: this was significantly higher than the incidence of apoptosis in the placental specimens of the latter (0.9+/-0.07 per cent, P< 0.02 Wilcoxon rank test). The same results were obtained with H&E: the incidence of apoptosis detected in placentas from the former was 1.07+/-0.1 per cent compared to 0.72+/-0.08 per cent in those of the latter (P< 0.02 Wilcoxon rank test). CONCLUSIONS: Despite similar environment conditions, placental apoptosis is increased in the smaller fetus and thus might play a role in discordancy between twins. Since increased placental apoptosis has also been found in singleton intrauterine growth restriction, this supports the hypothesis that the smaller twin is selectively growth restricted.

Increased erythrocyte adhesiveness and aggregation in peripheral venous blood of women with pregnancy-induced hypertension.

OBJECTIVE: To study the state of erythrocyte adhesiveness/aggregation in the peripheral blood of women with pregnancy-induced hypertension as well as in matched controls using a simple slide test and image analysis. METHODS: We recruited 25 women with pregnancy-induced hypertension. Twenty-five age- and gestational age-matched normotensive volunteers took part in the study and served as controls. Blood smears were evaluated by an image analysis system (INFLAMET). Quantitative measures of erythrocyte aggregation were used to describe the state of erythrocyte adhesiveness/aggregation such as vacuum radius, which measures the spaces between the aggregated erythrocytes. The number of participants was established by power analysis (given alpha of 0.05 and 80% power and considering a minimum difference to detect 4 microm in vacuum radius with a standard deviation of approximately 5). RESULTS: A significant (P =.002) increment in the state of erythrocyte aggregation was noted in the study group compared with the controls, the vacuum radius values being 16.1 +/- 1.3 and 10.3 +/- 1.2, respectively. Erythrocyte sedimentation rate but not fibrinogen concentration was significantly elevated in the study group. The increased aggregation correlated significantly with fibrinogen concentration, systolic, and diastolic blood pressures. CONCLUSION: We observed increased aggregability of red blood cells in hypertensive conditions of pregnancy. Our findings are significant in that they reveal blood pressure-related increment in red cell adhesiveness/aggregation despite there being no significant increment in clottable fibrinogen concentrations.

Fresh and frozen-thawed human sperm bind in a similar pattern to the zona pellucida in the hemizona assay.

This study evaluated the impact of sperm cryopreservation on sperm quality. The HZA was used to test the binding capacity of fresh as opposed to frozen-thawed sperm from 12 donors. Fresh and frozen-thawed sperm motility was 47% +/- 1.5% and 24% +/- 3.8% (mean +/- SE), respectively. However, the number of sperm cells attached to the hemizonae was 75 +/- 12.0 and 74 +/- 11.9, respectively. We conclude that cryopreservation results in a reduced number of motile sperm cells but does not adversely affect the ability of rescued sperm cells to bind to the ZP. The study also supports the use of frozen-thawed rather than fresh donor sperm for control in the HZA procedure.

Zona pellucida binding improvement effect of different sperm preparation techniques is not related to changes in sperm motility characterizations.

OBJECTIVE: To study the relation between changes in sperm motion characteristics and sperm binding capacity to the zona pellucida (ZP) after different sperm preparation techniques. DESIGN: Prospective study. SETTING: Andrology laboratory at the Lis Maternity Hospital. PATIENT(S): Sixty-three infertile men. INTERVENTION(S): In vitro preparation of 57 sperm samples by pentoxifylline (PTX), 38 samples by SpermPrep I (SP1), and 27 samples by mini-Percoll (mPER). Sperm preparation was evaluated in comparison with the control washing technique. MAIN OUTCOME MEASURE(S): Motility variables and binding capacity. RESULT(S): Binding capacity after PTX, SP1, and mPER preparation methods was significantly higher compared with the control medium preparation. Computer-assisted sperm analysis (CASA) of sperm motility revealed a significant increase in a number of variables after the different treatments. A statistically significant but low correlation was observed between sperm binding capacity after control swim-up preparation and VAP (r = 0.27) as well as with VSL (r = 0.30). No significant correlations were found between the changes in the CASA and the improved sperm binding to the ZP. CONCLUSION(S): The two biologic effects of binding capacity enhancement and motility features improvement are not related. Furthermore, because the binding assay is highly correlated with fertilization capacity, these alterations in motility, as evidenced by CASA, probably have a minor effect on fertilization in vitro.

The effect of egg yolk on the binding capacity of human spermatozoa to zona pellucida.

OBJECTIVE: To evaluate the effects of Tes and Tris (TEST)-yolk buffer (TYB) incubation on sperm function. DESIGN: Sperm samples obtained from 61 patients attending the infertility clinic were incubated in TYB and control medium. Binding to the zona pellucida (ZP), evaluated by the hemizona assay, membrane functional integrity evaluated by the hypoosmotic swelling test, and acrosome reaction and penetration through cervical mucus were assessed to ascertain the effect of TYB treatment. RESULTS: The only substantial effect of TYB treatment was enhanced sperm binding to the ZP. The mean number of sperm cells attached to the hemizonae with TYB or medium treatment, was 42 +/- 6.1 (+/- SE) and 31 +/- 5.8, respectively (n = 61). However, this improvement was most obvious in 12 patients whose sperm samples exhibited a marked increase in sperm binding capacity following TYB treatment compared to medium without TYB, 71 +/- 5.6 and 12 +/- 2.7, respectively. In the other sperm samples (n = 49), sperm binding capacity was similar following TYB and medium treatment (both 35 +/- 6.0). CONCLUSIONS: A 2-hour incubation of sperm samples with TYB-containing medium (at room temperature) enhances the binding capacity of human spermatozoa in approximately 20% of patients considered to have male factor infertility. The basis of this selective effect has yet to be studied further.

Evaluation of meiotic impairment of azoospermic men by fluorescence in situ hybridization.

OBJECTIVE: To identify predictive criteria for the existence of spermatogenesis in nonobstructive azoospermic men. DESIGN: Prospective study. SETTING: Andrology laboratory at a teaching hospital. PATIENT(S): Twenty-two azoospermic men were divided into three groups by qualitative testicular histopathology and the presence of spermatozoa in minced biopsies. INTERVENTION(S): Testicular biopsies evaluation. MAIN OUTCOME MEASURE(S): The presence of spermatozoa and/or mature spermatids, the percentage of sex vesicle formation (X and Y chromosomes in proximity), and the pairing of the two 18 homologous chromosomes. RESULT(S): Spermatozoa and mature spermatids were found in 17 study patients. Whenever few mature spermatids and/or spermatozoa were found, the rates of X-Y and 18 bivalents were significantly higher (mean +/- SD, 73% +/- 13. 3% and 91% +/- 7.1%) than those in cases of spermatocyte maturation arrest (23% +/- 8.0% and 60% +/- 11.8%, respectively). CONCLUSION(S): Pairing of chromosomes during meiosis is apparently related to the progression of spermatogenesis. Consequently, high rates of bivalent formation increase the prospect of focal spermatogenesis in the testis, despite the failure to identify mature spermatids in the specific testicular biopsy under examination.

The hemizona assay is of good prognostic value for the ability of sperm to fertilize oocytes in vitro.

OBJECTIVES: To assess the prognostic value of hemizona assay (HZA) in predicting the success of IVF. DESIGN: Samples from 133 patients, who were referred for semen evaluation, were tested by HZA. Thirty samples were tested twice to assess interassay variation. Seventy couples were also referred for IVF. Results of HZA were compared with standard parameters of sperm quality, fertilization rates, and pregnancies. RESULTS: The intra-assay and interassay coefficient of variation were 8% and 14%, respectively. Hemizona assay results had the highest correlation with sperm morphology (r = 0.60). Of all parameters evaluated, fertilization rates were best predicted by hemizona index (HZI) (r = 0.75). The assay was found to have high sensitivity and specificity rates, at a threshold HZI of 23%. CONCLUSIONS: The HZA is a valuable prognostic test for IVF. With a threshold HZI of 23%, it has a good predictive value for fertilization rates in IVF, and may thus be used for patient preselection before IVF.

Expression of mannose-ligand receptors on human spermatozoa: effect of lecithin and association with sperm binding to the zona pellucida.

OBJECTIVE: To evaluate the change in the expression of mannose-ligand receptors and sperm binding capacity after the incubation of sperm cells with lecithin liposomes. DESIGN: A randomized, blinded-controlled experiment. SETTING: Andrology laboratory at the Lis Maternity Hospital. PATIENT(S): Fifteen fertile sperm donors and 10 subfertile men. INTERVENTION(S): Incubation of sperm samples with either control medium or 1 mg/mL of liposomal lecithin for 2 hours. MAIN OUTCOME MEASURE(S): Expression of mannose-ligand receptors as evaluated by mannosylated bovine serum albumin-fluorescein isothiocyanate and sperm binding to the zona pellucida as evaluated by the hemizona assay. RESULT(S): The mean +/- SE percentages of spermatozoa with patterns I, II, and III were 86% +/- 4.8%, 11% +/- 3.4%, and 3% +/- 1.6%, respectively, after treatment with control medium and 71% +/- 5.7%, 22% +/- 3.5%, and 7% +/- 2.5%, respectively, after treatment with lecithin. The same effect of lecithin was observed in the 10 sperm samples from subfertile men. The mean +/- SE numbers of sperm that bound to hemizonae after treatment with control medium or lecithin were 116 +/- 32.4 and 176 +/- 29.6, respectively. Statistically significant correlations were observed between the shift in patterns II and III and the enhancement of sperm binding after lecithin treatment (r = 0.44 and 0.6, respectively). CONCLUSION(S): Lecithin shifts the expression of mannose-ligand receptors to the capacitated and acrosoine-reacted patterns and enhances the binding capacity of the sperm cells.

Pentoxifylline improves sperm binding to the zona pellucida in the hemizona assay.

OBJECTIVE: To evaluate the effect of pentoxifylline on sperm binding capacity to zona pellucida (ZP) using the hemizona assay (HZA). DESIGN: The fertility potential of 82 men was evaluated by routine semen analysis. Each ejaculate was incubated with or without pentoxifylline (3 mM) in Ham's F-10 medium (Flow Laboratories, Irvine, Scotland) before the HZA. The effect of the pentoxifylline treatment on sperm-binding capacity to ZP was assessed by the hemizona index. RESULTS: The mean hemizona indexes with medium or pentoxifylline treatment were 23% +/- 2.1% (mean +/- SE) and 41% +/- 3.4%, respectively. Taking into consideration a significant change of the hemizona index on rising above the intra-assay coefficient of variation (+/- 8%) after pentoxifylline treatment, 73.1% of specimens improved, 19.5% deteriorated, and 7.4% remained unchanged. Using a threshold hemizona index of 23% as a discriminator between fertile and infertile specimens, 43.5% of the "pentoxifylline-improved" samples ascended to the fertile zone (> 23%). No correlations were found between sperm variables in the raw semen and the effect of pentoxifylline on sperm binding capacity. CONCLUSION: Pentoxifylline may improve the binding capacity of human spermatozoa. However, this effect is confined to a selected group of patients and cannot be predicted by the basic sperm variables. Thus, to avoid uncertain or damaging effects of pentoxifylline while preparing sperm suspension for assisted reproductive techniques, it is recommended that its effect be tested by the HZA system before its use.

Levels of vascular endothelial growth factor are elevated in patients with ectopic pregnancy: is this a novel marker?

OBJECTIVE: To determine serum levels of vascular endothelial growth factor (VEGF) and evaluate their capacity to serve as a marker for the diagnosis of ectopic pregnancy (EP). DESIGN: Prospective, case-controlled study. SETTING: A tertiary care center. PATIENT(S): Twenty women with EP, 10 women with normal intrauterine pregnancy, and 10 women with abnormal intrauterine pregnancy, all at comparable stages of gestation. INTERVENTION(S): Serum samples were obtained from all women. MAIN OUTCOME MEASURE(S): All samples were analyzed for VEGF, progesterone, and beta-hCG by specific methods. RESULT(S): Women with EP had higher serum levels of VEGF than women with normal intrauterine pregnancy and women with abnormal intrauterine pregnancy (median levels, 226.8 pg/mL, 24.4 pg/mL, and 59.4 pg/mL, respectively). With a cutoff level of 200 pg/mL, serum VEGF could distinguish intrauterine from extrauterine pregnancy with a sensitivity of 60%, specificity of 90%, and positive predictive value of 86%. CONCLUSION(S): The increased serum VEGF levels in women with EP may facilitate this challenging diagnosis and reduce maternal morbidity and mortality.

Three-generation evaluation of Y-chromosome microdeletion.

Sperm cells can be retrieved directly from the testis (testicular sperm extraction [TESE] procedure) and used for intracytoplasmic sperm injection (ICSI), circumventing underlying spermatogenetic defects. Thus, it is important that added information be available on the genetic defects in men undergoing TESE for the ICSI procedure and on the transmission of genetic factors associated with infertility to the offspring. We report a three-generation genetic analysis of a family with a case of male factor infertility. The proband, previously diagnosed as infertile, was physically examined and laboratory tested for gonadotrophic hormones, semen analysis, karyotype and Y-chromosome microdeletion screening in the blood and testis. The Y-chromosome microdeletion screening was performed by multiplex polymerase chain reaction with 20 Y-chromosome sequenced, tagged sites located at the Y chromosome. A microdeletion including the AZF-c region was detected in the azoospermic patient. His father, four brothers, and three offspring born after ICSI also underwent Y-chromosome microdeletion screening. The genetic analysis of the male members of the patient's family did not reveal similar microdeletions. The newborn male was found to bear a Y-chromosome microdeletion similar to that of his father. The fertilization capacity of the proband testicular microdeleted spermatozoa by the ICSI procedure is described. The transfer of the genetic defect raises the possibility that the son will have the same fertility problem as his father.

Morphology of testicular spermatozoa obtained by testicular sperm extraction in obstructive and nonobstructive azoospermic men and its relation to fertilization success in the in vitro fertilization-intracytoplasmic sperm injection system.

The aim of the present study was to evaluate the morphology of testicular spermatozoa by 3 different determinants. Sperm cells were obtained and their morphology was evaluated from 27 testicular sperm extraction (TESE) operations, of which 20 men had nonobstructive azoospermia and 7 had obstructive azoospermia. In 17 cases, 2 biopsies were obtained from 2 different locations of the testis. Only mature spermatozoa presenting full-grown tail (tail dimension about 10-fold greater than the head dimension) were counted. Three characteristics of sperm morphology were evaluated: head dimensions, and acrosome and midpiece irregularities. The percentage of sperm cells with normal morphology (considering the 3 characteristics) in specimens from patients with obstructive and nonobstructive azoospermia were 47% +/- 4.6% and 29 +/- 1.8%, respectively (P < .01). The percentage of spermatozoa with normal head dimensions were 76% +/- 3.2% and 63% +/- 2.6% (P > .05), those with normal acrosome were 58% +/- 4.6% and 41% +/- 3.4% (P < .05), and those with normal midpiece were 74% +/- 4.1% and 67% +/- 1.6% (P > .05), in obstructive and nonobstructive azoospermia, respectively. No significant differences were observed in sperm morphology between different locations of the testis. Sperm morphological characteristics were not associated with fertilization rate in intracytoplasmic sperm injection (ICSI). Follicle-stimulation hormone and luteinizing hormone were inversely correlated with normal morphology of testicular spermatozoa (r = -0.49 and r = -0.47, respectively; P < .05). It can be concluded that a relatively high portion of testicular sperm are morphologically normal. The higher rate of normal spermatozoa in obstructive azoospermia compared with nonobstructive spermatozoa suggests that the factors leading to azoospermia may affect testicular sperm morphology. The morphological characteristics of testicular sperm do not affect fertilization rate in ICSI.

The progestative effect of the levonorgestrel-releasing intrauterine system--when does it manifest?

The objective of the study was to evaluate, clinically and sonographically, the time required for the progestative effect of the levonorgestrel-releasing intrauterine system (IUS, Mirena) to be manifested. Doppler flow of the cervical branch and spiral artery of the uterine artery, as well as the endometrial width (up to day 10 of the cycle), were evaluated in 36 women carrying levonorgestrel-releasing IUS 1-2 months after insertion of the device compared to 4-6 months after insertion. The rate of intermenstrual bleeding was reduced from 44% during the first 2 months, to only 8% of women after 4-6 months of use. Complete cessation of menstrual bleeding occurred in 5% after 2 months and in 66% after 4-6 months following insertion. While there was no change in the Doppler flow in the cervical branch of the uterine artery between both groups, there was a significant reduction in the subendometrial flow in the spiral artery. This observation was reinforced by the demonstration of significant reduction in endometrial thickness in the following 4 months of use. The present study has demonstrated that the local progestative effect of the levonorgestrel-releasing IUS on the endometrium is already manifested within a period of 3 months and over after insertion.